1. Field of the Invention
The invention relates to a circuit arrangement using semiconductor elements with a temperature-dependent current/voltage characteristic for generating a signal when a critical temperature of a power semiconductor component is exceeded.
2. Description of the Prior Art
Such a circuit arrangement has been described e.g. in the German journal "elektronik industrie" 4-1985, pages 32-38. In this circuit arrangement, so-called "band gap" references are used for temperature sensing. The temperature-dependent forward voltage of one or more diodes is evaluated by means of a thermally-stable operational amplifier. Thus a voltage signal corresponding to the temperature is obtained, which signal is processed by a comparator for further treatment e.g. in a logic circuit. This circuit arrangement is relatively costly, in particular due to the requirement of a thermally-stable operational amplifier.